net/mlx5e: Add mqprio_rl cleanup and free in mlx5e_priv_cleanup()

In the cited commit, mqprio_rl cleanup and free are mistakenly removed
in mlx5e_priv_cleanup(), and it causes the leakage of host memory and
firmware SCHEDULING_ELEMENT objects while changing eswitch mode. So,
add them back.

Fixes: 0bb7228f ("net/mlx5e: Fix mqprio_rl handling on devlink reload")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>